Materials and methods
We reviewed retrospectively data of consecutive 246 patients with COM
who underwent surgical management at our hospital between Jan 2019 to
Dec 2020. 173 patients with pre-and postoperative pure tone audiometry
data were included in the analysis. Exclusion criteria included patients
with revision surgery, adhesive otitis media, and unsuccessful surgical.
The surgical procedures were performed by one otology surgeon. The
selection of surgical approach is determined by the range of lesion as
well as the preoperative status of hearing and facial nerve function.
All procedures involving human participants followed the institutional
research committee ethical standards in accordance with the 1964
Helsinki declaration and its later amendments. This was retrospective
study, thus no informed consent was needed.
Pure tone audiometry was conducted in a double-chamber anechoic room
using standard procedures. All patients had pre-operative pure tone
audiometry within one week of surgery. Air conduction threshold (AC),
bone conduction threshold (BC), and air-bone gap (ABG) were tested at
250, 500, 1000, 2000, and 4000 Hz, respectively. One year following
surgery, the same methods were used to examine post-operative pure tone
audiometry. At these frequencies, changes in AC, BC, and ABG were
calculated between pre- and postoperative examinations. Statistical
analysis was performed for each frequency by comparing pre-and
postoperative mean values. A positive value indicates improvement and a
negative value indicates deterioration.
Based on possible influence factors, these COM patients were
retrospectively categorized into three subgroups (Table 1): group A
(based on the type of surgical method), tympanoplasty vs. canal
wall-down tympanoplasty; group B (based on the type of ossicular
replacement), partial ossicular replacement prosthesis (PORP) vs. total
ossicular replacement prosthesis (TORP) vs. none; group C (based on the
type of tympanic membrane repair material), temporalis fascia vs. tragus
cartilage.
Statistical analyses were performed using SPSS 21.0 software. The
metering data were expressed as mean ± SD and the significance analysis
using t-test. The categorical variables were compared using the
Chi-square test or Fisher’s exact test. P < .05 indicates that
the difference is statistically significant.
Table 1 Distribution of cases in different groups.